"On Thursday afternoon, Facebook banned the group on the basis of attempting to delegitimize the election process, and its role in potentially instigating physical violence." No shit. Democracy is hanging by a thread in the US right now, with a president trying to shut down the democratic count and vote counters fearing for their life from crazies on the right. This is the right move.
If you look closely you'll find that group is trying to draw attention to election irregularities. Facebook is not an arbiter of truth, it's a platform for staying in contact with others. And as such shouldn't have an opinion either way. Once it steps outside of that role it's on a hiding to nothing as all sides will find fault - as they are.
Have they actually pointed any irregularity?
I see a lot of Trump fanatics parroting blatantly false and baseless claims involving all sorts of convenient irregularities, but so far I've seen zero actual evidence supporting any of the claims.
If there is indeed a massive wave of election fraud then where's the evidence?